An organism made of fungus and green algae or cyanobacteria is called a lichen.

Here's a breakdown of the relationship:

* Fungus: Provides structure and protection for the lichen. It absorbs water and nutrients from the environment.

* Green algae or cyanobacteria: Provides food through photosynthesis. They use sunlight to produce sugars, which the fungus can then use.

This relationship is a symbiotic one, meaning both organisms benefit. The fungus gets food from the algae/cyanobacteria, and the algae/cyanobacteria get protection and a stable environment from the fungus.